The purpose of the work was to study the influence of the sporiferous probiotics «Subtilis» and «Provagen» on the productive qualities, viability, haematological parameters of cross «Ross-308» broiler chickens. The research was conducted according to the standard techniques. The feeding value of the complete feeds met the regulations of the All-Russian research institute of technology of poultry farming and recommendations for this cross. The
Feeds were given to appetite. Probiotics were added to the complete feed at the enterprise by manual mixing just before feeding the birds. The main housing conditions of chickens (microclimate parameters, light regime, chicken density, feeding and drinking space) were identical for all groups and corresponded to «The Ross-308 broilers raising guide» (2009) and to the recommendations of the All-Russian research institute of technology of poultry farming (2008). As a result it was found that using of probiotics «Subtilis» and «Provagen» in
broiler chickens feeding had positive impact on their growing capacity. Introduction of the test probiotics into the complete feeds of broiler chickens promoted improvement of zootechnical indicators of their rearing (increase in live weight, average daily gain, chick livability and reduction of feed costs per 1 kg of live weight gain). Using of probiotics had positive impact on the metabolic status and the general body resistance of birds, that was evident by the increase in quantity of erythrocytes in blood of chickens of the experimental groups, hemoglobin, total protein, albumines and globulins, increase of the bactericidal and lysozyme activity of blood serum. The best results were obtained in the 3rd group. In this group probiotic «Provagen» was added to the complete feeds for broilers in a dose of 0,015 g/bird. (1х109CFC/bird) per day (0,2 kg/t) during the first 7 days of rearing.